Ramandeep

Invertebrate are animals that do not have a backbone or a bony skeleton.scientists have identified nearly one million living species of invertebrates but this rep resents only a small fraction of the total number of invertebrates  alive today. invertebrates alive today are perhaps as many as 30 million species of living.eamal beetles have couler full and hard coated. the common fruit fly drosophila melangaster has been used. Invertebrates defy nearly every generality. Of some 30 phyla representing  95 to 99 percent of the planet's animal species, the only thing they have in common is what they lack: a backbone. Otherwise, you would be hard pressed to find similarities among species as distinct as enormous moths, ethereal medusas, skittering scorpions, or stationary sponges. They may be spineless, but don't disregard these wildly diverse creatures: They're everywhere, and they have us seriously outnumbered...and outweighed. Scientists calculate that in the U.S., the combined weight of earthworms, insects, and spiders is 55 times greater than that of humans. Members of the phylum Porifera, ("pore-bearer") are commonly known as sponges, and approximately 5,000 have been described by scientists. Until the 18 th century, scientists mistook them for plants. Found worldwide in marine and fresh water environments, the sponges are notable for their unique feeding system. Specialized collar cells pump a current of water through pores into the sponge, which then filters out nutrients. Though simple in design, sponges have strikingly bold colors and elaborate shapes. For instance, the aptly named orange puffball sponge,  Tethya aurantia, is mostly spherical and orange to yellow in color. The delicately latticed Venus' flower basket sponge,  Euplectella aspergillum, often shelters pairs of shrimp and as a result was once a symbol of marital fidelity in Japanese weddings.